Typical cold and allergy relief remedies are sold in liquid or capsule formulations and are generally administered orally. Although such remedies may work well for relieving some allergy or cold symptoms, the effectiveness of many of these remedies may be limited due to, for example, digestive processes in the oral and digestive pathways. For example, enzymatic activity in the oral cavity and/or acidic environments present in the digestive system may degrade the performance of specific elements or compounds comprising active substances in cold or allergy relief compositions. A further disadvantage of typical compositions involves the circuitous routes some active ingredients are forced to travel, such as when orally administered substances must travel from the oral cavity to the nasal cavity for interaction with active sites in the nasal membrane. For example, these difficulties may be particularly acute when orally administered zinc must travel from the oral cavity up to the ICAM-1 receptor sites on the nasal membrane. Further, effective migration of these active substances may be further impeded when taken by a congested person, often the type of person most in need of these types of nasally bound substances, where the route from the oral cavity to the nasal cavity is blocked or partially blocked by the congestion. Accordingly, a method of delivering active substances to the body which bypasses these degenerative systems is desirable.
Alternative cold and allergy relief techniques involve intravenous administration of the active substances. Such techniques are generally not considered an acceptable commercial alternative to oral application of drugs due to consumer preferences and safety concerns, among others. Transdermal delivery is another alternative delivery method. However, this approach is generally not well suited for all types of active ingredients due to, among others, the significant challenges present in delivery of therapeutically effective amounts of active substances across the epidermal barrier.
Another approach involves nasal cavity administration where active substances are administered directly into the nasal cavity. Many prior attempts at nasal drops and sprays have failed because the active ingredient fails to remain in contact with the nasal membrane for a sufficient period of time, thereby preventing the effective rendering of therapeutically acceptable benefits. For example, typical nasal drops and sprays contain liquid matrices having a low viscosity. Upon application, the liquid tends to be drawn out of the nasal cavity by gravity. The active substance is then prevented from contacting the nasal membrane for an extended period of time sufficient to render a desired therapeutic benefit. For example, some sprays have been observed to dissipate from the nasal cavity in less than five minutes after a first application, which may not allow some active ingredients to remain in contact with the nasal membrane for a sufficient amount of time.
Various methods have been developed attempting to prevent the liquid from dissipating from the nasal cavity, including insertion of cotton swabs and nose plugs into the nasal cavity to prevent leakage. Here too, however, prior methods have proved problematic. Consumers tend to find nose plugs of any type uncomfortable and view them as cosmetically unappealing. Such devices also discourage additional applications of the composition to the nasal membrane as the plug must be removed and reinserted each time. Finally, most plugs tend to contact the nasal membrane directly, which tends to draw the composition away from the nasal membrane due to the absorbent effects of the various materials used to make the plugs.
Accordingly, a composition effective at facilitating contact of an active substance with the nasal membrane for an effective amount of time is needed, and in particular, a composition comprising a decongestant. Moreover, an effective composition and method to deliver an active substance, and in particular a decongestant, to the nasal membrane is also needed.